I tried searching for this and couldn't find anything. My converter is shot so I need a new one and figured I'd just get a cheaper catco one and have a mechanic put it on.

I have a RKSport rear exhaust section, so i'm assuming it will have a 2.5" diameter...but how long should it be? I am just going to order it off www.summitracing.com but they have all different lengths from 11 to 14 and even 21 inches. Any help from someone who has done this or ordered one would be helpful.

Thanks in advance.